New genetic tests — and what inequities in healthcare have Leave a comment

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A new genetic test might help doctors identify individuals facing an increased risk of heart attacks “long before they have them,” Gina Kolata writes for the New York Times.

A new genetic test may predict heart disease risk

A new genetic test, known as a polygenic risk score, analyzes thousands of genetic variants to assess heart disease risk. While each genetic variant may only partially contribute to risk, evidence suggests that the variants combined might indicate which patients are likely to have heart attacks.

“Cardiologists hope to use such tests, which cost about $150 and are not typically covered by health insurance, to identify people most likely to have heart attacks long before they have them,” Kolata writes. “Some doctors envision testing children as part of routine pediatric care.”

Individuals identified as high risk would receive aggressive treatment. Meanwhile, patients who are identified as low risk may be spared from unnecessary treatment.

“There’s a real unmet need to identify high-risk people very early in life,” said Nicholas Marston, a cardiologist at Brigham and Women’s Hospital who has studied polygenic risk scores and been involved in trials for pharmaceutical companies that make cholesterol medicines. “We know the solution to preventing heart disease is getting your bad cholesterol as low as possible for as long as possible.”

Currently, guidelines largely reserve cholesterol-lowering statin treatments for individuals ages 40 and older. However, “high cholesterol levels damage blood vessels slowly, over a period of decades,” Kolata notes. A polygenic risk score may help doctors determine which patients have a high enough risk for early intervention.

Sadiya Sana Khan of Northwestern University underscored the need for more research. In her new study, she found that CT scans of the heart were better predictors of risk in middle-aged to older adults. “But that leaves a question about how to manage risk in young people, who almost never have visible plaque on a CT scan, even if they are at greater danger for a heart attack later in life,” Kolata writes.

“We need more studies that focus on younger people with follow-up over several decades,” Khan said.

In particular, Khan questioned whether young adults identified as high risk will be more likely to have a heart attack later in life or if they will simply be “needlessly worried about their hearts,” Kolata writes.

Ultimately, experts believe polygenic risk scores are likely here to stay. Researchers at Geisinger are creating strategies for introducing them, including clinical trial planning.

“I predict it will be part of routine care,” said Christa Martin, Geisinger’s chief scientific officer. “We will treat it no differently than cholesterol screening or screening for diabetes.” (Kolata, New York Times, 5/30)